This report describes two cases of multicentric Castleman's disease associated with Kaposi's sarcoma, and reviews the literature. With the recent delineation of a multicentric variant, Castleman's disease has evolved as a disease entity with a wide clinical spectrum ranging from localized, reversible disease as originally described by Castleman et al., to a generalized disease that is rapidly progressive and fatal. The latter represents the most severe form of the disease in which the associated immune derangement predisposes the patients to infections and Kaposi's sarcoma.